Abstract:
A method of manufacturing hot rolled steel strip from continuously cast input stock in successive work steps includes adjusting strip-shaped input stock after solidification to hot rolling temperature and introducing the input stock into a multiple-stand rolling mill for rolling into finished strip. The rolled stock is heated by an inductive heating unit at least between the first stand and the second stand.
Abstract:
The invention relates to a method for conditioning double metal catalysts which are used in the production of polyether polyols. The conditioning enhances the performance of the catalyst, so that lower concentrations of the DMC catalyst can be used in polyether polyol production.
Abstract:
Method of determining the composition of polymer mixtures comprising defined polymer components of differing mean molar masses Mn, which comprises the steps (a) recording of at least one 1H-NMR relaxation curve of the polymer mixture and (b) calculating the proportions of the polymer components by matching the measured relaxation curve with the relaxation curves of the individual polymer components. In this way, the composition of polymer mixtures can be determined quickly and simply. Furthermore, process integration for regulating the polymerization is possible.
Abstract:
In a method of selecting polymerization catalysts, in particular Phillips catalysts for the polymerization of olefins, from a multiplicity of catalysts on the basis of their catalytic properties, a multiplicity of catalyst precursors or catalyst supports are converted in parallel into polymerization catalysts in a pretreatment step in an array of reactors, where the pretreatment comprises at least one thermal treatment step at from 250 to 1200° C. Furthermore, at least one starting material is converted with the aid of the respective polymerization catalysts under prescribed polymerization conditions into at least one polymer product in a polymerization step and, finally, analysis of the polymer product or products is carried out to determine its composition and/or chosen properties. This makes it possible to carry out a thermal pretreatment of polymerization catalysts quickly under defined conditions which can be varied.
Abstract:
When rolling sheets or strips in roll stands using working rolls, which are supported on back-up rolls or on intermediate rolls having back-up rolls, whereby the setting of the roll gap is effected by axially displacing roll pairs provided with curved contours, differences from the required profile occur in the instance of larger widths of a product range due to excessive extensions in the edge areas or in the quarter areas that are manifested in the form of so-called quarter waves in the flatness of the product. In order to rectify this problem by using a simple mechanism and to improve the setting mechanism and the strategy for creating absolutely planar strips with a predetermined thickness profile over the entire width of the rolling stock, the invention provides that for forming the roll gap set profiles (10, 11) for two selected displacing positions, the contours of the rolls of one roll pair are shaped in such a manner that they produce, in the roll gap, a profile (20, 21), which is symmetric with regard to the center of the roll and which has a profile maximum in the center of the roll that can be altered by displacing the rolls, whereas the contours of the rolls of at least one second roll pair produce, in the roll gap, a profile (22, 23), which is symmetric with regard to the center of the roll and which has two identical maxima outside of the center of the roll that can be altered by displacing the rolls.
Abstract:
The present invention relates to plastic containers or moldings which have been produced by blow molding and have improved antistatic properties. The containers or moldings have an outer wall and an inner wall and contain webs of electrically conducting material running along the inner wall. The invention also relates to a process for the production of the containers or moldings and to their use.
Abstract:
A multilayer composite plastics material, containing at least one layer (A), which consists, to an extent of least 90 wt %, based on the total weight of this layer, of ethylene homopolymers or copolymers, at least one barrier layer (B), which substantially consists of polybutylene terephthalate, and also, if desired, layers of adhesion promoter (C) serving to improve the adhesion between these layers.
Abstract:
The inner wall of a solids reactor for carrying out reactions in the gas phase is coated with an antistatic layer having a thickness of 0.1-800 &mgr;m and consisting essentially of a poly-&agr;-olefin and a nonvolatile antistatic agent.
Abstract:
A method of operating a rolling mill for hot-rolling and cold-rolling of flat products in one or more roll stands each having two or more rolls, wherein the roll gaps are regulated so as to correct the differential force between the drive side and the operator side of the roll stands, while compensating the adjustment value-controlled regulation of the roll gaps which corrects the bending and balancing forces. Prior to further processing of the flat products, the regulation is supplied with an additional correction adjustment value formed from the horizontal forces measured in all individual rolls.
Abstract:
Catalyst systems which are suitable for the polymerization of olefinically unsaturated hydrocarbons contain, as active components, A) an amidinato metal complex of the formula A ##STR1## where M is a metal from group IIIb, IVb, Vb or VIb of the Periodic Table of Elements or a metal from the lanthanide group, X is a negative leaving atom or a negative leaving group, and the radicals X may be identical or different if (n-m)>1, R.sup.1, R.sup.2 and R.sup.3 are each a C-organic or Si-organic radical, n is the valency of M in the metal complex A and m is from 1 to 5, with the proviso that n-m.gtoreq.0, and, B) an activator in a molar ratio of activator B to metal complex A of from 0.5:1 to 10,000:1.